The invention relates to improvements in apparatus for introducing metered quantities of liquids into bottles, cans or other types of containers.
Heretofore known filling apparatus employ a vessel (hereinafter called tank for short) which stores a supply of liquid, and a plurality of so-called filling heads which are equipped with shutoff valves and serve to transfer metered quantities of liquid from the tank into discrete containers which are delivered to positions of register with the outlets of the filling heads. As a rule, or at least in many instances, the liquid is discharged by gravity and flows into a container as long as the respective shutoff valve remains open.
If the liquid in the tank is maintained at an elevated pressure, e.g., if the liquid is a carbonated beverage, the apparatus employs filling heads which are designed to raise the pressure in the containers prior to admission of liquid so that the pressure in an empty container which is about to receive a metered quantity of liquid matches the pressure of liquid in the tank. The step of raising the pressure in an empty container prior to admission of a metered quantity of liquid includes the introduction of a compressed gas which is thereupon expelled from the container by the inflowing pressurized liquid. In many instances, the filling heads which are used for admission of pressurized liquids comprise pipes serving to confine the expelled compressed gases to the flow into the gas-filled space above the body of liquid in the tank. The liquid can fill the tank to a level which is below the upper (discharge) ends of the aforementioned pipes, and its upper level fluctuates which is not conducive to the admission of accurately metered quantities of liquid into each of a short or long series of containers in the form of bottles, cans, jars or the like. Moreover, it is difficult to rapidly alter the quantities of liquid which are to be admitted into containers.